The present invention relates to air traffic control; and in particular, to a method and a system for collaborative coordination of traffic flow rerouting needed under severe weather conditions to minimize the input of severe weather on the National Airspace System (NAS).
Further, the present invention relates to particular traffic flow management using a proactive decision support tool based on accurate convective weather forecasts for rerouting aircrafts around forecasted areas of severe weather while maintaining safe levels of controller""s workload and minimal traffic delays.
The present invention also relates to managing traffic demand in sectors adjacent to weather constrained areas in order to maximize throughput while avoiding exceeding the available capacity of such sectors.
The present invention further relates to rerouting traffic around severe weather areas, where the plan of rerouting aircrafts is automatically assessed based on affected sector loading, extra air miles flown, total aircraft delay, and ground delay. In this manner, if the assessment is deemed to be non-satisfactory, a rerouting plan may be modified by adding, removing, or modifying traffic designated routes.
The present invention is further related to a traffic flow management system automated to an extent which permits quick creation, modification, and rerouting assessment plans, in order to permit collaboration with human traffic controller specialist. Subsequent to such collaboration, the plan, if accepted, is communicated electronically to Air Traffic Control for implementation with strict time requirements. The entire process is based on weather forecasts which are updated frequently, to permit traffic flow management reroute plans to be updated accordingly.
During recent years, increased air traffic has intensified the input of severe weather on the National Airspace System (NAS), which leads to delays, cancellations, increased miles flown, greater schedule uncertainty, and other undesirable air traffic changes. To respond to difficulties in traffic flow management associated with severe weather conditions, several systems have been developed to alleviate air traffic delays caused by severe weather.
For example, a Collaborative Rerouting Coordination Tool (CRCT) has been developed by the Federal Aviation Administration""s Center for Advanced Aviation System Development, aided by The MITRE Corporation, McLean, Va. The baseline CRCT is a set of decision support capabilities being developed to evaluate and demonstrate traffic flow management concepts. The baseline CRCT is currently in daily use and is being operationally evaluated at the Air Traffic Control System Command Center and the Air Route Traffic Control Center. The baseline CRCT includes functionality for rerouting around manually generated Flow Constrained Areas (FCAs), automatic identification of aircraft predicted to enter FCAs, manual rerouting of aircraft around FCAs, and automatic assessment of the input of proposed reroutes on sector traffic volume.
In baseline CRCT, a Traffic Management Specialist (TMS) manually draws an FCA polygon to represent an area impacted by weather or other factors that limit traffic flow. Disadvantageously, manual FCA generation is practical only when few FCAs are needed and the weather is generally stable and predictable. This is often not the case with convective weather patterns, which may consist of many storm cells moving at various speeds and directions and involving complex cell growth, decay, splitting, and merging. Therefore, there is still the need for a system which would enhance the baseline CRCT to make it more practical, precise and automated.
Other flight rerouting systems have also been developed. For example, U.S. Pat. No. 4,086,632 is directed to a generic flight plan rerouting system which includes a map display unit for establishing and modifying navigation routes. When it becomes necessary to modify a previously established navigation route or to reprogram the central computer with a new navigation route during flight, a map control unit is implemented.
The map control unit includes a plurality of switches for controlling display of a program navigation route, entering new way-points to modify an existing navigation route or establish a new route, and deleting way-points from a previously established route. Signals representative of the positions of these control switches are coupled to the central computer of the system for initiation of the necessary computational operations and appropriate output signals are coupled from the central computer to the map display unit to provide an appropriate visual display.
U.S. Pat. No. 5,797,106 is directed to a method and apparatus for an improved flight management system which provides for linking of an outbound course line from a predetermined position with an existing flight plan. If the flight crew selects a course modification from a specified way-point, the flight crew enters a way-point name xe2x80x9cXXXxe2x80x9d into the flight management computer, and the system displays the course direction on the flight management computer. The system creates a discontinuity flight plan between the course line and the remainder of the flight plan and displays the discontinuity as a sequence of boxes on the flight management computer legs page. Further, the flight management system creates a flight plan modified state in the flight management computer. The flight crew is further given the opportunity to either approve or disapprove the outbound course entry. If the flight crew decides to accept the entered outbound course, the system determines whether or not the newly entered course line intersects the downstream leg of the originally entered flight plan. If the course line does not intersect the downstream flight leg of the presently entered flight plan, the system provides the flight crew with the option to incorporate a new outbound course line into the flight plan.
U.S. Pat. Nos. 5,715,163; 5,340,061; and, 5,047,946 are all directed to aircraft navigational systems and methods for guiding an aircraft with the option of rerouting and modification of flight plans.
Although these known flight rerouting systems all have mechanisms for calculating new navigational paths depending on a newly desired way-point, none of them is automated to an extent which permits the user to estimate and choose the best reroute option depending on a multiplicity of factors, such as flight status, number of reroute options available for each flight, availability and capacity of reroute sectors, as well as controller""s workload threshold in sectors, the ability of a flight to execute the proposed reroute and equitable allocation of scarce resources in a time-satisfactory manner. Such prior art systems have not been based on use of weather forecast products for flight plan calculations, assessing and modification, where the weather forecast products are frequently updated to permit flight rerouting plans to be automatically updated accordingly.
Therefore, it is clear that an improved traffic flow management weather rerouting decision support tool free of the disadvantages of the prior art is still needed in the industry.
It is an object of the present invention to provide a method and system for effective weather rerouting decision support based on frequently updated weather forecasts, as well as on the basis of a plurality of associated factors in very time-optimized and safe manner.
It is additionally an object of the present invention to provide a system and method of traffic flow management for weather problem resolution which evaluates rerouting plans for flights that are in conflict with weather based on several parameters specified by the traffic management specialist. The system performs an optimization of the plan or plans to determine which flights will be assigned to each designated reroutes based on optimization criteria such as minimizing arrival delays while staying within the controller""s workload limits for each designated reroute.
It is a further object of the present invention to provide a rerouting system which evaluates the rerouting plan and, upon plan evaluation, displays the evaluation results which include statistics on flight delays and the number of aircraft rerouted as well as information about the flights that were not able to be incorporated into the rerouting plan. The non-incorporated flight results include the number of flights that could not find a slot on any designated reroute, and the number of flights that would have had to be turned too sharply to reach a designated reroute.
It is a still further object of the present invention to provide a traffic management system for rerouting flights under severe weather conditions which generates predicted sector loading based on the plan reroutes to avoid unacceptable work loads for sector controllers.
It is a further object of the present invention to provide a system and method for rerouting aircraft around the areas of severe weather in which the planned reroutes are evaluated, in order that the plan may be modified to add new reroute corridors in order to avoid congested areas, or delete ineffective reroute corridors. The new plan may then be evaluated in order to produce a new set of reroutes with the results of the new plan being assessed. The cycle may be repeated until the traffic management specialist is satisfied that the plan moves flights past the weather as efficiently and safely as possible.
According to the teachings of the present invention, there is provided a method for weather problem resolution in air traffic flow management which includes the steps of:
automatically deriving flow constrained areas (FCAs) from a weather forecast product (such as National Convective Weather Forecast, Collaborative Convective Forecast Product, etc.);
generating a candidate flight list including conflict flights which are predicted to be affected by the FCAs;
for each conflict flight, in a predetermined priority order, generating a plurality of available reroute corridors;
selecting the best available reroute corridor from the generated plurality of available reroute corridors;
calculating a four-dimensional trajectory for reroute of the each conflict flight onto the best available reroute corridor;
based on the four-dimensional trajectory, estimating workload of sectors (the geographical regions where single controller teams control air traffic) affected by rerouting the each conflict flight onto the best available reroute corridor; and
accepting the best available corridor for the each conflict flight if the estimated sector workloads are below pre-set workload levels.
If, however, the workload of a sector is above the pre-set workload level each conflict flight is further checked for whether it may be ground delayed, and for how long, in order to avoid exceeding the pre-set workload level in the sector. The best available re-route corridor will be rejected for each conflict flight if the ground delay is impossible. After the rejection of the previously selected best available re-route corridor, another best available re-route corridor is selected from the plurality of available re-route corridors generated initially for each conflict flight.
Each conflict flight has a cost associated with use of a generated re-route corridor. The best available re-route corridor with respect to cost is selected based on the least possible cost which is determined by additional miles flown, ground delay, air delay, or total arrival delay associated with flying on or from the selected re-route corridor.
The method further comprises the steps of displaying (1) the automatically generated FCAs as polygons on a traffic display, and (2) the available re-route corridors.
The candidate flight list is sorted to provide a priority order of processing each flight in accordance with predetermined sorting criteria, which may be based on flight status (flight in the air or on the ground), predicted time of arrival to the problem area, or any other sorting criteria which may be changed as needed.
The plurality of available re-route corridors may be generated manually by a human traffic management specialist, or they may be unloaded from a data base of previously generated re-route corridors.
Each re-route corridor has restriction parameters associated therewith which include a list of fixes which each conflict flight flies through on the reroute corridor, a range of altitude which each conflict flight is allowed to use on the re-route corridor, a range of times when the re-route corridor is open, and the maximum turn angle which the conflict flight may use to turn onto or from the re-route corridor. Each of the plurality of generated available corridors has associated restriction parameters satisfying a conflict flight.
The four-dimensional trajectory predicted for each flight includes predicted locations and altitudes of the conflict flight at future times and is calculated based on the filed flight plan, conflict flight positions, upper air winds, air traffic control restrictions, NAVAID and airport locations, preferred routes, aircraft performance data, airport delay performance, etc.
Viewing another aspect of the present invention there is provided a traffic flow management system for weather problem resolution which includes:
an ability to ingest a weather forecast product,
processing mechanisms operatively coupled to the weather forecast product for deriving flow constraint areas (FCAs) therefrom,
a traffic display coupled to the processing mechanism for displaying the FCAs thereon,
a mechanism for predicting conflict flights affected by the FCAs and for generating a candidate flight list of the conflict flights,
means for sorting the candidate flight list to establish a priority order of the conflict flights in accordance with the predetermined priority criteria,
means for manually generating a plurality of available re-route corridors for each of the conflict flights in the order of the established priority, wherein each available re-route corridor meets the specific restriction parameters for each conflict flight,
means for selecting the best available re-route corridor from the plurality of the generated available re-route corridors in accordance with the cost of the conflict flight associated with the re-route corridor,
means for calculating a four-dimensional trajectory for re-route of the each conflict flight onto the best available route corridor, and
means for estimating a sector workload effected by re-routing of the conflict flight turning to the best available re-route corridor.
The traffic flow management system for weather problem resolution of the present invention further includes means for comparing the estimated workload of the sector with a pre-set workload level,
means for searching for ground delay of the conflict flight if the estimated workload exceeds the preset workload, and
means for searching for another best available re-route corridor if the ground delay of the conflict flight is unavailable.
These and other objects and features of the present invention will become more apparent from the following detailed description of the present invention considered in connection with the accompanying drawings which disclose an embodiment of the present invention. It should be understood, however, that drawings, as well as the description, are presented here for the purpose of illustration only and not as a definition of the limits of the invention.